Evaporator



March 27, 1934.

H. E. THOMPSON EVAPORATOR Filed Feb. 3,1952 2 Sheets-Sheet 1 INVENTOR. #171919? E Tflom/wolv.

flu/WM ATTORNEYS.

March 27, 1-9 4. H E TH MP ON 1,952,827

EVAPORATOR Filed Feb. 3, 1932 2 Sheets-Sheet 2 INVENTOR. Hflnn Y E. Thom/ J0 1v.

BY W

ATTORNEY.

Patented Mar. 27, 1934 UNITED STATES EVAPORATOR Harry E. Thompson, Detroit, Mich, assignor to Universal Cooler Corporation, Detroit, Mich.,'a corporation of Michigan Application February 3,

Claims.

different sized evaporators may be provided by l0 merely incorporatinginto different evaporators a determined number of units, This permits of making up the units in desired quantities all more or less of a standard form, and the building of evaporators therefrom by merely assembling a desired number of units into a single evaporator structure.

The invention also contemplates an evaporator which makes economical use of the refrigerant.

It will be appreciated that refrigerant in liquid form may enter the evaporator; the refrigerant becomes gasified therein thus absorbing heat. The particular structure is arranged sothat at r the location where the refrigerant passes away from the evaporator an unusually large heat absorbing surface is employed in order to insure eflicient or substantially complete evaporation of the refrigerant. The large contacting or heatab'sorbing surfaces may be afforded by fins constituting a part of the evaporator structure. The

invention has to do particularly with an evaporator of the type employed in the so-called dry system of mechanical refrigeration. In the accompanying drawings: Fig. 1 is a view partly in front elevation and 36 partly in section illustrating the evaporator structure taken substantially on line 1--1 of Fig. 2.

Fig. 2 is a top plan view thereof. Fig. 3 is a side view partly in side elevation an 40 partly in section. Fig. 4 is a sectional view taken through a modified form.

Fig. 5 is a sectional view taken through a modified form. i

a The invention is concerned largely with an evaporator structure constituted by metal units which advantageously may be cast metal. In conjunction with the cast metal units, suitably shaped or coil tubing is employed for association with the .50 units, the tubing containing the refrigerant; The,

' metal employed in the evaporator structure may be aluminum, and such metal is preferred as it" provides for relatively light overall weight and at the same time provides for adequate thermal conductivity. The invention of course isnot to be 1932, Serial No. 590,684

limited to aluminum as other metals may be employed.

Referring now to Fig. 1, it will be noted that the evaporator shown comprises two units each providing a sharp freezing chamber. One of such 0 units is shown at 1 preferably in the form of a hollow casting, and another of such units is shown at 2, of similar or identical structure. The hollow castings provide each a sharp freezing chamber, and the rear ends of these chambers 65 may be closed as by means of closure plates 3 (Fig. 3) which may be of suitable metal such as copper, aluminum or the like, and which may be secured to the castings in any suitable manner, as for example, screws 4. The rear closures 3 may 7 be cast integral with the body of the' units.

The bottom of the evaporator may be constituted by a plate 5, also advantageously of cast aluminum. This bottom member may be of grillework or slat formation, as illustrated in Fig. 3, constituted by slats or cross bars 6 disposed in spaced relation. This has the effect of lightening the structure. The member may be strengthened crosswise as by means of a rib 8, and the forward end of the unit may have a boss 9 which may be provided with a threaded aperture 10. Also this member may have apertured bosses 11, the purpose of which will presently appear.

The top of the unit may comprise a member, also advantageously of cast aluminum, and having 5 a body portion of plate formation, as illustrated at 12, integral with-which may be, fins 13. As shown in Fig. 2, there may be a considerable number of such fins, and as illustrated in Fig. 1, they may depend from the body 12 so as to extend downwardly adjacent the sides of the unit 1. These depending portions are illustrated at 14 and may be termed wings, and theymay be spaced from the side walls of the unit 1, as shown. The top member may also have apertured bosses 15.

'The evaporator unit, as shown in Fig. 1, comprises two similar units each providing a sharp freezing chamber, a lower bottom member and a top member preferably finned. These are disposed in the relation shown, and then they may-1 be secured together by bolts or the like 16 taken through the apertured bosses 11 and 15. Refrigerant tubing is provided and preferably disposed between the several parts making up this unit. The inlet end of the tubing is illustrated at 20, 10 (Fig. 3) and then 'the tubing is in the form of a winding or coil 21 disposed between the bottom of the casting '2 and the bottom member 5. The tubing has a run 22' which may extend upwardly at the back of the unit and joined into a winding 11 or coil 23 between the two units 1 and 2. The inlet end 20 may be adjacent one side of the unit, and the run 22 adjacent the opposite side. The tube may have a run 24 preferably at the back of the unit extending upwardly and connecting into a winding or coil 25 between the topof the unit 1 and the top member 12, with the outletend of the tube coming from the winding 25 as illustrated at 26.

Accordingly, the refrigerant entering at 20 passes through the winding 21, and in so doing traverses the width of the evaporator, then passes through run 22 into winding 23. The refrigerant again traverses the width of the evaporator in passing through coil 23, and then passes out through run 24 and into coil 25 again traversing the width of the evaporator, and finally out at the'end 26. The bolts 16 may be tightened down to tightly engage the windings of the tube between the parts. Preferably, some of the casting may be provided with grooves in which the windings of the tube seat, which serve to position the windings cf the tube and hold the same fixed, and which also serve for additional contacting area. In this regard the top member 12 may be grooved for receiving the runs of the coil 25; the bottom wall of the casting 1 may be grooved for receiving the runs of the coil 23, and the bottom of the member 2 grooved for receiving the runs of the coil 21. As an aid for lining up and maintaining the units from shifting, the units 1 and 2 may have projections 30 which are spaced apart and between which the bolts 16 extend, as shown in Fig. 2.

A modified form of the invention is shown in Fig. 4, and in this form the parts and arrangement is the same as that shown in-Fig. 1 save for the fact that the unit 2' is larger than the unit 1. Otherwise the parts have the same reference characters applied thereto as in the form shown in Figs. 1, 2 and 3. This large unit 2' provides a large sharp freezing chamber so that it is capable of receiving a relatively large or oddly shaped article of food or the like, such as a block of ice cream. This chamber may have ribs 31 so that ice cube trays of the size which may fit the ordinary unit, such as the unit 1, may be placed in the larger unit 2 with one tray supported on the ribs 31 and one on the bottom of the unit. In the modified form shown in Fig. 5, the entire unit is of one-integral casting with the metal thereof cast around the tube. This casting, as shown, has a bottom wall. 35, a top wall 36 andan intermediate wall 37. These are connected by side walls 38. The fins 39 may be cast in--,

tegral therewith and have depending wings 40. The refrigerant tube may be arranged in-a manner similar to that shown in Figs. 1, 2 and 3; the coil 21' is confined within the metal of the bottom wall 35, the coil 23 confined in the wall 37, and the coil 25. confined in the top'wall 36. The bottom wall 35 ,may be corrugated, as shown, which serves to lighten the structure.

It will be noted that an evaporator constructed of units such as shown in Fig. 1 may be built up to any size by'merely employing the desired number of units, it being necessary only to have different lengths of bolts 16 to hold the structure assembled, and also to have the requisite number of coils in the tubing. The top and bottom casting members may be the same in all instances. By merely substituting a large unit such as 2' in Fig. 4, a differently shaped evaporator may be provided.

In use the unit may be provided with any suitable ornamental front piece, and for this purpose the top member 1 may have apertured bosses 42, these bosses together with the apertured boss 9 of the bottom member may be employed for attachment of any suitable front to the evaporator. The refrigerant entering the lowermost coil traverses the evaporator from side to side and has an efiicient relation to the evaporator in absorbing heat therefrom. The refrigerant then traverses the evaporator from side to side from coil 23 absorbing heat therefrom, and then finally traverses the width of the evaporator through the top coil 25. As the refrigerant is about to pass away from the evaporator as when it is in coil 25,-it is desirable that complete, or substantially complete, evaporation of the refrigerant takes place. For this purpose the heat absorbing surfaces constituted by the fins are provided adjacent the top coil. The result is that the heat exchange relation between the refrigerant in the last coil and the air currents surrounding the evaporator is greater than the heat exchange relation as regards the previous or first coils. Thus a final relatively great heat exchange relation is provided at the time the refrigerant is about to leave the evaporator to the end that the refrigerant is substantially'all gasified or evaporated.

I claim:

1. An evaporator comprising, a plurality of hollow metal members each constituting a sharp freezing chamber, a bottom member, a top member, a refrigerant conduit arranged in coils' between the bottom member and a chamber, and between the sharp freezing chambers, and between the top member and adjacent sharp freezing chamberhaving its outlet end adjacent the top member, and heat transfer fins on said top mem-, ber.

2. An evaporator comprising, a plurality of hollow metal members eachconstituting a sharp freezing chamber, a bottom member, a top member, a refrigerant conduit arranged in coils between the bottom member and adjacent sharp freezing chamberand between the sharp freezing chambers and between the top member and adjacent sharp freezing chamber having its outlet end adjacent the top member, and heat transfer fins on said top member, said fins having wings extending therefrom and disposed on opposite sides of the adjacent sharp freezing chamber.

3. An evaporator comprising a pair of hollow members placed oneabove the other and each constituting a sharp freezing chamber, a refrigerant coil between the members, a bottom member below the lowermost sharp freezing. chamber, 7 a refrigerant coil between said bottom member and lowermost sharp freezing chamber, a top member above the uppermost sharp freezing member, a refrigerant coil between said top member and uppermost sharp freezing chamber, conduits connecting the coils, radiating fins on the top member, and means connecting the top and bottom members clamping the sharp freezing chambers and coils between said members and holding the same in assembled relation.

5. An evaporator comprising, a plurality of members forming sharp freezing chambers, a

refrigerant conduit having an inlet end, said conduit adjacent the inlet end having coils in direct heat exchange contact with the outer side of one of the sharp freezing chambers, said conduit having intermediate coils in direct contact with adjacent Walls of two sharp freezing chambers, said conduit having an outlet end, said conduit having radiating fins in heat exchangerelation substantially only with the last mentioned coil for providing a relatively great heat transfer relation between the last mentioned coil and the surrounding air. 7

HARRY E. THOMPSON. 

